1. Technical Field
This disclosure relates generally to surgical needle forming apparatus and, more particularly, to a progressive die apparatus and method for forming surgical incision member blanks from double pointed needle stock, and the resulting surgical incision member blank.
2. Description of Related Art
Surgical incision members are surgical grade suturing needles having points formed at one or both ends preferably include surgical suturing apparatus engagement structure formed within a body portion of the needle intermediate the pointed ends. Particular surgical incision members are disclosed in U.S. patent application Ser. Nos. 08/260,579, filed Jun. 16, 1994 entitled SURGICAL INCISION MEMBERS now allowed; 29/024,594, filed Jun. 16, 1994 entitled SURGICAL INCISION MEMBER; 07/954,013 filed Sep. 30, 1992 entitled SUTURING APPARATUS now abandoned; and 08/134,145 filed Oct. 8, 1993 entitled SURGICAL SUTURING APPARATUS WITH LOADING MECHANISM, now abandoned the disclosures of which are incorporated by reference herein. The suturing apparatus engagement structure is provided in the body portion of the surgical incision members to cooperate with corresponding engagement structure, such as, for example, needle engaging numbers or blades, on various surgical suturing apparatus. One particularly suitable apparatus for manipulation of surgical incision members is disclosed in U.S. patent application Ser. No. 08/134,145 filed Oct. 8, 1993 entitled SURGICAL SUTURING APPARATUS WITH LOADING MECHANISM. Apparatus engagement structure in the body portion of the needle blank along with cooperating engagement structure on the surgical suturing apparatus facilitates repeatedly passing the surgical incision member between a pair of arms or jaws in the suturing apparatus. In this manner the surgical suturing apparatus is able to securely and precisely control the surgical incision member for very effective, rapid and precise suturing of tissue. The apparatus engagement structure may be in the form of notches, holes, or crimps, etc., formed in the body portion of the surgical needle.
Additionally, surgical incision members may have various suture attachment structure formed in the body portion intermediate the pointed ends. Preferably, the suture attachment structure is positioned intermediate the apparatus engagement structure. The surgical incision members may be curved having a radius substantially equal to the distance between a pivot point and engagement structure on a pair of jaws. Alternatively, the surgical incision member may be relatively straight to facilitate transfer of the surgical incision member between a pair of parallel moving jaws or arms. The parallel moving arm or jaw structure may be in the form of arms or jaws which move perpendicular to each other axis or parallel to each other. One or both jaws of the suturing apparatus may move.
Due to the added manufacturing equipment necessary to produce apparatus engagement and suture attachment structure within the body portion of a needle, the manufacture of surgical incision members may often become complicated and costly. For example, one method of manufacturing the surgical incision member is by a process called metal injection molding or "MIM". The MIM manufacturing process tends to be very costly and thus may adversely affect the otherwise desirable characteristics and traits of a surgical suturing apparatus utilizing surgical incision members.
The production of needles in general involves many processes and different types of machinery in order to prepare quality needles from raw stock. These varying processes and machinery become more critical in the preparation of surgical grade needles where the environment of intended use is in humans or animals. Some of the processes involved in the production of surgical grade needles include, inter alia, straightening wire stock, cutting needle blanks from the wire stock, tapering or grinding points on one or both ends of the blank, and providing structure for receiving a suture thread at an end of the blank or at a location intermediate the ends. As used herein, the term "needle blank" refers to a piece of needle stock at various stages of completion but not fully formed into a surgical grade needle suitable for use during surgical procedures. Additionally, one skilled in the art will appreciate that flat surfaces may be formed on sides of the blank, typically by flat pressing portions of the needle blank to facilitate grasping by surgical instrumentation. Curving of the needle blank may also be performed where curved needles are desired. When providing curved needles for surgical procedures it is desirable for the needles to have a specified curvature, i.e., a predetermined radius of curvature. The desired radius of curvature for the finished needle varies with specific applications. Further, when surgical grade needles are made of steel or similar resilient materials, the curving anvil or mandrel used should have a smaller radius than the desired radius of the final surgical needle. This configuration allows for a "springback" or radial expansion effect after the curving operation to ensure that the desired radius of curvature is attained.
Surgical incision members typically require several processes to form the finished product. These processes may include curving and cutting needle stock to form needle blanks, altering or refining the tip configurations and curvature radius, punching or drilling the blank to form a suture hole and/or notching the blank to provide engaging structure for cooperative instrumentation.
Conventional needle processing is, in large part, a labor intensive operation requiring highly skilled labor and sophisticated machinery. One disadvantage to conventional needle processing is that most needle processing operations, such as, for example, cutting the blanks from stock, tapering the stock to form points, flat and side pressing of the body portion of the blanks, curving the blanks, notching, hole drilling, etc., are performed in batch operations on separate processing machines.
Thus, it would be desirable to have an apparatus for forming a large number of surgical incision members in a very short time and with a minimal amount of machinery. It would further be desirable to have an apparatus and a method of forming curved surgical incision members having a desired radius of curvature. It would be still further desirable to have an apparatus and a method of simultaneously imparting apparatus engagement structure and drill point guide holes in the body portion of a needle blank.